Electrically conductive spring contact structures on an electronic device can make temporary, pressure based electrical connections with terminals or other such input and/or outputs of a second electronic device. For example, the spring contact structures on the electronic device can be pressed against the terminals of the second electronic device to make temporary electrical connections between the spring contact structures and the terminals and thus between the electronic device and the second electronic device. Embodiments of the present invention are directed to improvements in such spring contact structures, processes of making such spring contact structures, and applications of such spring contact structures.